This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This project is designed to clarify the mechanisms which underlie Thyroid hormone receptor (T3R) isoform specific effects in the heart. We will investigate the functional role of T3R in the cardiac myocytes and heart microvascular endothelial cells. In addition, the distribution of the different isoform of T3Rs will be determined in the different cell types.